import math


def fluctuation_ratio(fund_net_value_list):
    length = len(fund_net_value_list)
    avg = 0
    for i in range(0, length):
        avg += fund_net_value_list[i]
    avg = avg / length

    total = 0
    for i in range(1, length):
        total += (fund_net_value_list[i] - avg) * (fund_net_value_list[i] - avg)
    return math.sqrt(242 / (length - 1))


print fluctuation_ratio([1.0, 1.0, 1.0])
